<!DOCTYPE html>
<html>
  <head>
    <link rel="stylesheet" href="vscode-file://style.css">
    <style>
      @import url("vscode-file://imported.css");
      button {
        background: url(background.png);
      }
    </style>
  </head>
  <body>
    <button>Click me</button>
  </body>
</html>
